By Denise Mann
health day reporter
TUESDAY, Nov. 29, 2022 (HealthDay News) — Overweight or obese children often struggle with school homework, and now new research is providing clues about how being overweight can harm brain development.
“The main takeaway is to raise awareness of the consequences of obesity on brain health in addition to the consequences on physical health, especially since obesity rates are very high and continue to rise,” said study author Simone Kaltenhauser, a postdoctoral researcher in radiology and biomedical imaging at Yale Medical School in New Haven, Connecticut.
According to the US Centers for Disease Control and Prevention, approximately one in five American children is obese.
For the study, researchers looked at several types of brain scans in more than 5,100 children between the ages of 9 and 10 who participated in the ongoing Adolescent Brain Cognitive Development (ABCD) study. Of these, 21% were overweight and 17.6% were obese.
What did they find? There were structural and functional brain deficits in overweight or obese children compared to children who were not, and these changes may contribute to poor school performance.
Specifically, overweight or obese children showed thinning of the outermost layer of their brain (the cortex), which has been linked to impaired executive functioning abilities, such as planning and juggling multiple tasks. Additionally, brain white matter integrity was impaired in the corpus callosum (which connects the two hemispheres of the brain) and in the pathways within the cerebral hemispheres that connect the lobes of the brain in overweight or obese children.
Additionally, brain networks involved in reward-based decision-making and behavior control showed reduced connectivity in overweight or obese children.
These patterns persisted for two years, the study showed.
“Our results provide an important potential explanation for other studies that show a higher body mass index [BMI] in children is associated with poor cognitive functioning and academic achievement,” Kaltenhauser said. (BMI is a measure of body fat that takes into account height and weight.)
It’s too early to tell if losing weight and increasing physical activity can offset some of these brain changes, but it’s possible, she noted.
“Brain plasticity, or the ability to reorganize neural pathways in children, is very high, and there is evidence in the literature that cognitive performance may increase after weight loss interventions,” Kaltenhauser said. “The ongoing ABCD study will collect data from its participants for several more years, allowing us to further track these changes over time.”
The results were presented Monday at the annual meeting of the Radiological Society of North America (RSNA) in Chicago. Results presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.
Dr Vincent Mathews said the new study helps connect some dots between excess weight and brain changes in children. “Previous research has shown that obesity is associated with poorer academic performance, impaired cognitive function and lower brain volume in children,” said Mathews, chair of radiology at the Medical College of Wisconsin to Milwaukee.
“This study shows changes in brain function and integrity of white matter pathways linked to childhood obesity, which potentially explain the impaired cognitive function and its effect on school performance,” Mathews added.
Some questions remain, he said. “It is not clear whether obesity precedes impaired brain function or whether the latter precedes the development of obesity at present,” Mathews pointed out.
Dr. Scott Kahan, director of the National Center for Weight and Wellness in Washington, DC, said most of the data on how obesity affects brain health relates to adults. “This study adds to the baseline of the literature in children,” he noted.
More research is needed to determine if carrying excess weight has a direct impact on the brain, or if poor diet and/or lack of physical inactivity are the culprits, or if factors that predispose people to obesity, such as lower socioeconomic status, also contribute to poor health. brain development, Kahan said.
The US Centers for Disease Control and Prevention offers advice on how to tackle childhood obesity.
SOURCES: Simone Kaltenhauser, postgraduate researcher, radiology and biomedical imaging, Yale School of Medicine, New Haven, Connecticut; Vincent Mathews, MD, professor, chair, department, radiology, Medical College of Wisconsin, Milwaukee; Scott Kahan, MD, director, National Center for Weight and Wellness, Washington, DC; November 28, 2022, presentation, annual meeting of the Radiological Society of North America (RSNA), Chicago